The present invention relates to an electric motor, in particular a DC motor.
The state of the art already discloses numerous electric motors comprising a cylindrical shell receiving at one at least of its ends a casing end flange provided with a roller bearing for the rotor shaft, the said flange being fixed to the cylindrical shell by fixing means.
However, these motors have a certain number of drawbacks, especially related to the mode of fixing the flanges onto the shell.
Specifically, generally, the end flanges are assembled and fixed onto the stator shell by crimping. The ends of the shell receiving the flanges are therefore deformed permanently, thereby degrading the magnetic performance of the stator and requiring complex crimping equipment on the motor assembly line.
In other cases, the flanges are screwed onto the shell, thereby increasing the number of components of the motor, the assembly time and the tooling cost.
A main aim of the invention is to remedy these drawbacks, and to propose an electric motor of the aforesaid type whose cost of assemblage is reduced and whose performance is not degraded on account of the assemblage operation.
According to the invention, the fixing means comprise a bayonet-type assembly, the assembling of the flange onto the shell being achieved through a relative displacement in axial translation and a rotary relative motion.
According to other characteristics of the invention:
the bayonet assembly comprises an L-shaped guidance aperture formed in the peripheral wall of the shell, and a complementary pin secured to the flange,
the fixing means comprise an elastic locking member intended for the relative rotational tying of the flange and the shell, when the latter are in the position of complete assemblage,
the elastic locking member comprises a flexible elastic tab carrying a lug, secured to one of the two components constituted by the flange and the shell, and cooperating with a window made in the counterpart component, and
comprises a commutator secured to the rotor shaft, a brush-carrying ring supporting two brushes displaceable between a standby position separated from the commutator and an active working position in contact with the commutator, the said ring being housed in the shell in the vicinity of one of its ends the corresponding end flange comprising two axially projecting members, each of which is intended to cooperate with a respective one of two brushes, in such a way as to displace the latter from its standby position to its working position when assembling the flange onto the shell.
By virtue of this latter arrangement, the unlocking of the brushes and their movement from their standby position to their working position is achieved automatically when assemblage of the motor is complete, that is to say when the end flange is mounted on the shell.
This operation is achieved without additional tooling, with no additional component, and also without any operation time being added to the motor assemblage time.
According to yet other characteristics of the invention:
each projecting member exhibits a ramp intended to cooperate with a ridge of the corresponding brush,
the ramp is configured so as to displace the corresponding brush to its working position during the relative displacement in axial translation of assemblage of the flange onto the shell,
the ramp is configured so as to displace the corresponding brush to its working position during the rotary relative motion of assemblage of the flange onto the shell.
The invention is also aimed at a drive device for motor vehicle equipment, comprising an electric motor as described above.